Electrical connector



N 1967 R. c. WILKINSON ETAL 3,351,890 Q ELECTR I CAL CONNECTOR Filed May 13, 1966 m w TN N mwm m m wm w g n IKE. A A H b um 0 4 C on OED muw mm United States Patent Navy Filed May 13, 1966, Ser. No. 551,180 6 Claims. (Cl. 339-443) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention is directed to an electrical connector and more particularly to an electrical connector Which is connected at right angles to a coaxial cable for connecting a coaxial cable to an ionization chamber while electrostatically shielding the signal lead with minimum current leakage to the signal lead.

Heretofore, coaxial cables have been connected to the output of an ionization chamber by crude connectors. However, problems exist due to humidity, which permit an excessive electrical leak between the outer shell of the detector and the inner conductor of the shielded cable connected thereto. Such an electrical leak due to weather conditions creates a situation wherein such ionization chambers must be checked and calibrated in a controlled environment. Other problems develop from the manner in which the cable has been connected to the ionization detectors.

The electrical connector of the present invention is adapted to be connected at right angles to a coaxial cable in order that an electrical circuit may be completed between the coaxial cable and the output of an ionization chamber. Thus, there is one less make/break point in the system. The connector is so constructed that the output of the ionization chamber is electrostatically shielded. The electrical connector provides an electrical connection between the output of an ionization chamber and the center conductor of a coaxial cable such that the outer conductive shell of the ionization chamber is insulated from the center electrical conductor and the outer conductor of the coaxial cable. The connector is so constructed that maximum insulation exists between the outer shell of the chamber and the center conductor of the connector.

It is therefore an object of the present invention to provide an electrical connector which is suitable for connecting the center conductor of a coaxial cable to the center pin output of an ionization chamber wherein the signal lead is electrostatically shielded over its entire length.

Another object is to provide an electrical connector in which the conductive shell of an ionization chamber is insulated from the outer conductor of a coaxial cable connected thereto through the electrical connector.

Still another object is to provide an electrical connector which provides a minimum electrical leakage between the shell of an ionization chamber and the center conductor of a coaxial cable connected to the electrical connector.

Yet another object is to provide an electrical connector which is permanently connected to a coaxial cable to provide one less make/ break point in the system thereby eliminating one source of possible electrical leakage between the conductors.

While still another object is to provide an electrical connector which is sufiiciently light in weight and ruggedly constructed so as to withstand vibrational forces of a launch vehicle, it launched into space.

The nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing in which:

The drawing is a cross-sectional view illustrating the relative parts thereof secured to a coaxial cable and to an ionization chamber which is only partially shown.

The electrical connector of the present invention is connected between a coaxial cable at right angles thereto and an ionization chamber such that the center pin of the ionization chamber is protected against electrical leakage between the center conductor of the connector, the outer shell of the ionization chamber, and the conductor elements of the coaxial cable which is connected to the electrical connector. The electrical connector is provided with a central conductor which is connected to the center conductor of a coaxial cable and to the center output pin of an ionization chamber and which is insulated from an outer conductor of the electrical connector which connects with the shell of the ionization. chamber. The electrical connector is provided with an insulator element which is assembled to prevent accidental short-circuiting of the ionization chamber polarizing voltage in case the connector is removed from the ionization chamber while the polarizing voltage is applied thereto. The connector is provided with a spring washer mechanism which provides a convenient means of connecting the polarizing voltage to the ionization chamber.

Now referring to the drawings, there is shown for illustrative purposes only, a cross-sectional view of an electrical connector made in accordance with the features of the present invention. The electrical connector includes an axially disposed cylindrical conductive element 11 surrounded by a cylindrical element 12 of insulator material in which one end of the electrical conductor and insulator material is smaller than the opposite end of the electrical conductor and insulator. The end of the insulator having the greater diameter is bore out on the inner surface thereof to a greater diameter than the smaller diameter end to receive therein the greater diameter end of the electrical conductor. The larger end of the electrical conductor is formed with split ends 13 which split extends linearly of the electrical conductor such that the split end portion is under tension to receive therein a male output element 14 of an ionization chamber 15 to which the electrical conductor is connected. The end of the electrical insulator element having the least outside diameter extends just short of the outer end of the electrical conductor at 16 whereas the end of the insulator having the greater diameter extends to the opposite end of the split end portion of the electrical conductor. The end of the electrical conductor having the greater diameter forms a shoulder 17 against which the electrical insulator rests and the larger end of the electrical insulator forms a shoulder 18, the purpose of which will be described later. A cylindrical conductive element 21 having an outwardly turned end portion 22 on one end thereof is extended over the small end portion of the insulator element with the outwardly turned end portion thereof resting against the shoulder 18 on the insulator element. The cylindrical conductive element is shorter than the small end portion of the insulator element such that the cylindrical electrical element does not extend to the outer end of the insulator element.

A cylindrical insulator element having a small end portion 23 and a large end portion 24 is provided with a passage therethr-ough such that the insulator element will pass over the cylindrical sleeve 21 and is provided with a counterbore 25 in the large end thereof to provide a shoulder 26 which fits against the outwardly curved end portion 22 of the cylindrical conductive sleeve 21 and also provides an axially extending end portion which passes around an electrical shield portion 27 of the ionization chamber when connected thereto. The counterbore is of sufiicient length that the shoulder 26 provided thereby rests against the outwardly turned end 22 of the cylindrical conductive element 21 while the larger diameter end of the insulator element fits against the conductive end portion 28 of the ionization chamber. A coupling sleeve 31 having an inwardly directed flange portion 32 which .has an axial passage therethrough of a diameter sufiicient to pass over the end 23 of the outer most insulating element and having a larger diameter end which passes over the larger diameter end 24 of the insulator element is provided on the inner surface of the larger diameter portion with threads 33. The threads thereon are such that they mate with a threaded portion 34 extending from the housing of the ionization chamber. A spring washer 35 having a passage therethrough of sufficient diameter that the washer will slide over the threads on the outwardly extending portion of the ionization chamber is placed between the coupling connector and the housing of the ionization chamber to provide a convenient means of connecting a polarizing voltage to the ionization chamber.

The opposite end of the electrical adapter is provided with a washer 36 made of insulating material and having an axial hole therethrough of sufficient diameter to pass over the electrical sleeve element such that the insulator washer 36 will rest against the outer end 23 of the insulator element. The purpose of the insulator washer is to prevent accidental short-circuiting of the ionization chamber polarizing voltage if the electrical connector is removed from the ion chamber while the voltage is applied. That is, the insulator washer prevents the coupling element from being screw-threaded oil of the ionization chamber connection and making contact with the head portion of a coaxial cable which is connected to the electrical connector.

In order to connect the electrical connector to a coaxial cable with the connector at a 90 angle relative to the axis of the cable, the end connector 37 of the coaxial cable has an aperture in the side as well as an aperture in the end thereof. A conductive sleeve 21 having the same outer diameter as the aperture in the side of the cable connector and an inner diameter slightly larger than the insulator 12 is soldered Within the aperture in the side of the end connector 37. The coupling sleeve 31 is then slipped over the insulator 23 and the washer 36 and insulator 23 is then slipped over the conductive sleeve, with the washer adjacent to the coaxial connector 37 between the coaxial connector and insulator 23. The end 22 of the cylindrical sleeve 21 is then turned outwardly to retain the insulator 23 and washer 36 in place. The

conductive element 11 is inserted into the smaller ins-ulator 12 with the end protruding therefrom and the small end of insulator 12 with the conductive element 11 therein is slid into the cylindrical sleeve 21 with the ends of each protruding into the area bounded by the coaxial cable connector. The center wire of the coaxial cable is then secured to the end of the conductive ele ment by solder or any other suitable method. The space in the coaxial cable connector 37 around the protruding end of insulator 12 and conductive element 11 is filled with epoxy resin to secure the insulator 12 and conductor 11 within the coaxial cable end connector. The epoxy resin prevents any lateral movement of both the insulator 12 and the conductor 11. Subsequent to filling the end connector with epoxy resin an end plug 41 is secured in the outer end of the coaxial cable connector.

It will be obvious to one skilled in the art that the various elements of the electrical connector may be assembled as a separate device and subsequent thereto the cylindrical conductive sleeve 21 inserted into an opening in the side of the coaxial cable end connector and secured thereto by solder or any other method. In the event the electrical connector is assembled separate from the coaxial cable end connector, the electrical connector may be assembled as follows, the center conductor is inserted into the insulator element surrounding the center conductor, then the conductive sleeve having the outwardly turned end is placed over the small end of the insulator with the outwardly turned end positioned against the shoulder of the insulator element 12. Then the outermost insulator is secured over the electrically conductive sleeve and the coupling member is placed over the insulator element such that the flange on the coupling is secured against the shoulder of the outer electrical insulator. The insulator washer is then placed over the end of the electrically conductive sleeve. The electrical connector is now assembled and ready to be secured to the coaxial cable and connector.

The electrically conductive sleeve is then slid into the aperture on the side of the coaxial cable connector soldered thereto and the center wire of the coaxial cable is connected to the center conductor as shown. The space around the end of the insulator 12 and the electrical conductive element 11 within the coaxial cable end connector is then filled with epoxy resin to secure the insula tor and conductive element within the coaxial cable end connector to prevent any lateral movement. The electrical connector then becomes an integral part of the coaxial cable connector and is ready to be secured to the output of an ionization chamber or any other suitable device. Prior to connecting the electrical connector to the ionization chamber, the conductive spring washer is placed over the screw-thread portion of the ionization chamber such that the spring washer will be secured between the end of the electrical adapter and the ionization chamber shell and in electrical contact with both. Thus polarizing voltage connected to the spring washer will provide an electrical voltage for the shell of the ionization chamber.

It can be seen when the electrical connector is connected to the screw-threads of the ionization chamber the electrical insulator about the center conductor of the electrical adapter extends sufficiently over the center pin conductor of the ionization chamber that there will not be any leakage of current from the end of the center conductor to the outer shell of the electrical adapter. Also the electrical insulator about the center conductor extends sufficiently into the coaxial cable connector that no current will pass between the end of the center electrical conductor and the outer shell of the coaxial cable connector or the cylindrical sleeve placed around the insulator of the electrical adapter. Thus, it can be seen that the electrical adapter of the present invention provides a suitable means of connecting a coaxial cable at right angles to the electrical conductors of an ionization chamber while providing good insulating qualities to prevent any current passage between the conductive elements due to atmosphere or other conditions.

For the purpose of carrying out the teaching of the present invention, the insulator elements may be made of any suitable insulator material; however, the preferred material is KEL-F (a polymer of triflouromonochlorethylene which is a trade name of M. W. Kellogg Co.) which is an exceptionally stable high temperature, non-flammable thermoplastic material. This material has excellent chemical resistance, has a high electrical resistance, and more important, it is exceptionally resistant to wetting by water or atmospheric conditions.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An electrical connector for connecting a coaxial cable at a right angle to the output of an ionization chamber wherein the connector includes:

a linear axially disposed electrical conductor element,

adapted to be connected electrically to the center pin of an ionization chamber and to the center wire conductor of a coaxial cable,

a first insulator element,

said first insulator element surrounding said conductor element over substantially the entire length thereof,

a conductive sleeve surrounding one end of said insulator element,

a second insulator element,

said second insulator element surrounding said conductive sleeve with a portion thereof spaced from and extending beyond the inner end of said cylindrical sleeve over and along a portion of said first insulator element,

a coupling,

said coupling extending over a portion of said second insulator element and including an inwardly extending flange that secures against a portion of said second insulator element,

said coupling including screw-threads on the inner surface thereof that screws onto matching threads of a connector.

2. An electrical connector as claimed in claim 1,

wherein:

said axially disposed electrical conductor has a solid end connection for connecting with the center Wire of a coaxial cable and a split-end portion for receiving an output pin-like conductor of an ionization chamber.

3. An electrical connector as claimed in claim 2,

wherein:

one end of said connector is inserted into an aper ture in one side of a coaxial cable end connecto; with said electrical sleeve in electrical contact witl said end connector and said center conductor is it electrical contact with the center conductor of saic coaxial cable.

4. An electrical connector as claimed in claim 3, whicl includes:

a spring washer electrical connector between said coupling of the electrical adapter and the ionization chamber housing when assembled.

5. An electrical connector as claimed in claim 4,

wherein:

said coupling prevents each of said elements against movement away from said ionization chamber.

6. An electrical connector as claimed in claim 2,

an insulator washer is secured over said electrical sleeve to prevent said coupling element from contacting the end connector of a coaxial cable to which the connector may be secured.

References Cited UNITED STATES PATENTS 3,111,356 11/1963 Mazzagatt et al. 339-77 X 3,323,097 5/1967 Tordoff 339-143 X MARVIN A. CHAMPION, Primary Examiner. J. R. MOSES, Assistant Examiner. 

1. AN ELECTRICAL CONNECTOR FOR CONNECTING A COAXIAL CABLE AT A RIGHT ANGLE TO THE OUTPUT OF AN IONIZATION CHAMBER WHEREIN THE CONNECTOR INCLUDES: A LINEAR AXIALLY DISPOSED ELECTRICAL CONDUCTOR ELEMENT, ADAPTED TO BE CONNECTED ELECTRICALLY TO THE CENTER PIN OF AN IONIZATION CHAMBER AND TO THE CENTER WIRE CONDUCTOR OF A COAXIAL CABLE, A FIRST INSULATOR ELEMENT, SAID FIRST INSULATOR ELEMENT SURROUNDING SAID CONDUCTOR ELEMENT OVER SUBSTANTIALLY THE ENTIRE LENGTH THEREOF, A CONDUCTIVE SLEEVE SURROUNDING ONE END OF SAID INSULATOR ELEMENT, A SECOND INSULATOR ELEMENT, SAID SECOND INSULATOR ELEMENT SURROUNDING SAID CONDUCTIVE SLEEVE WITH A PORTION THEREOF SPACED FROM AND EXTENDING BEYOND THE INNER END OF SAID CYLINDRICAL SLEEVE OVER AND ALONG A PORTION OF SAID FIRST INSULATOR ELEMENT, A COUPLING, SAID COUPLING EXTENDING OVER A PORTION OF SAID SECOND INSULATOR ELEMENT AND INCLUDING AN INWARDLY EXTENDING FLANGE THAT SECURES AGAINST A PORTION OF SAID SECONE INSULATOR ELEMENT, SAID COUPLING INCLUDING SCREW-THREADS ON THE INNER SURFACE THEREOF THAT SCREWS ONTO MATCHING THREADS OF A CONNECTOR. 